Imaging device

ABSTRACT

An imaging device  100  includes: an imaging element  110;  a main circuit substrate  120;  a mounting component  130  mounting the imaging element  110;  a metal plate  150  disposed between the mounting component  130  and the main circuit substrate  120;  a mount  140  supporting the metal plate  150  by connection sections  160  being fixed at at least three fixing points; elastic components  165  urging the connection sections  160  at each fixing point of the mount  140;  and an electrically-conductive component  190  electrically connecting between a ground conductor of the main circuit substrate  120  and the metal plate  150.  The electrically-conductive component  190  is disposed such that a connection point with the metal plate  150  is positioned in a area formed by the at least three fixing points being sequentially connected in the case of a back surface of the metal plate  150  being viewed in a direction orthogonal thereto.

BACKGROUND

1. Field

The present disclosure relates to imaging devices such as digital stillcameras and the like, and more particularly to imaging devices thatallow image interference caused by an external noise to be reduced.

2. Description of the Related Art

In recent years, opportunities are increased in which imaging devicessuch as digital still cameras and the like are used in environmentswhere portable information terminals, such as mobile telephones and PHSs(personal handyphone systems), which emit electromagnetic waves, areused. Further, there may be opportunities of imaging devices such asdigital still cameras and the like being used in environments whereintense electromagnetic waves are emitted, e.g. in the vicinity of aradio station or a television station.

In a case where the imaging device is used in such an environment, theimaging device is likely to be subjected to an electromagneticinterference. Hereinafter, an environment in which imaging devices arelikely to be subjected to such an electromagnetic interference isreferred to as an “intense electric field environment.” If an imagingdevice such as a digital still camera is used in the intense electricfield environment, an image taken by the imaging device may contain astripe pattern noise (beat noise), and image interference may be caused.

The higher a performance of an imaging element of the imaging device is(the higher the sensitivity of an imaging element to be used is), themore significant the image interference is. Further, in an imagingelement built into an imaging device having been downsized as a resultof the sizes of imaging devices being reduced, an amount of coupling ofintense electric field noise from the outside is increased, so that theimage interference becomes more significant.

Causes of the image interference include entering of an externalelectromagnetic wave into an image signal line of an imaging element.Therefore, as the conventional arts, a structure is disclosed in whichan electrically-conductive filter is additionally provided on a surfaceof a lens, and an imaging element is shielded from intense electricfield noises which may enter the imaging element (see, for example,Japanese Laid-Open Patent Publication No. 2008-211378).

SUMMARY

The inventors of the present application have considered that a metalplate is mounted to the reverse side of a mounting component formounting an imaging element, in order to dissipate heat generated in theimaging element. However, when the metal plate is subjected to anelectromagnetic wave from the outside, the metal plate secondarilyradiates the electromagnetic wave. Although heat generated in theimaging element is dissipated by means of the metal plate, the metalplate enhances electromagnetic field noises that enter the imagingelement. To address such a problem, the inventors of the presentapplication have considered that a metal plate is electrically connectedto a ground conductor of a main circuit substrate in order to stabilizea potential of the metal plate. In this case, an electrically-conductivecomponent that is connected to the ground conductor of the main circuitsubstrate is pressed against the back surface of the metal plate.

On the other hand, the inventors of the present application haveconsidered that the metal plate is fixed to a mount at three or morefixing points because the imaging element may be tilted if the metalplate is tilted. However, in a case where, for example, an elasticcomponent is provided at each fixing point in order to adjust thetilting of the metal surface, if the electrically-conductive componenthaving been pressed against the back surface of the metal plate isinappropriately disposed, the metal plate may be tilted, which may causethe imaging element to be tilted.

Therefore, the present disclosure is to make available an imaging devicethat allows an image interference caused by an external noise to bereduced while preventing an imaging element from tilting also when theimaging device is used in intense electric field environments.

The present disclosure is directed to an imaging device that allowsimage interference caused by an external noise to be reduced. In orderto attain the aforementioned object, the imaging device of the presentdisclosure includes: an imaging element configured to capture an opticalimage of an object, and generate image data; a main circuit substrate,disposed behind the imaging element, configured to perform signalprocessing of the image data generated by the imaging element; amounting component configured to mount the imaging element; a metalplate, disposed between the mounting component and the main circuitsubstrate, having a front surface on which the mounting component ismounted; a mount, disposed in front of the metal plate, configured tosupport the metal plate by connection sections extending forward fromthe metal plate being fixed at at least three fixing points; a pluralityof elastic components, provided at each fixing point of the mount,configured to urge the connection sections; and anelectrically-conductive component configured to electrically connectbetween a ground conductor of the main circuit substrate and the metalplate. The electrically-conductive component is disposed such that aconnection point with the metal plate is positioned in a area which isformed by the at least three fixing points being sequentially connectedin the case of a back surface of the metal plate being viewed in adirection orthogonal thereto.

For example, the connection point is positioned in an area in which themetal plate and the imaging element overlap each other in the case ofthe back surface of the metal plate being viewed in the directionorthogonal thereto. Further, the electrically-conductive component is anelectrically-conductive elastic component formed to be elasticallydeformable.

A compression load from the mount toward the metal plate is applied toeach elastic component. In a case where a compression load from the maincircuit substrate toward the metal plate is applied to theelectrically-conductive elastic component, in a state where the imagingelement is positioned to be orthogonal to a horizontal direction, a sumof compression loads applied to all the elastic components is greaterthan the compression load applied to the electrically-conductive elasticcomponent when the number of the electrically-conductive elasticcomponents is one, and a sum of compression loads applied to all theelastic components is greater than a sum of compression loads applied toall the electrically-conductive elastic components when the number ofthe electrically-conductive elastic components is plural.

The main circuit substrate has the ground conductor embedded therein. Inthe main circuit substrate, an introduction portion is formed, as anopening or a cut portion, in a portion of an insulating layer thatcovers the ground conductor, on a surface on the metal plate side, andthe electrically-conductive component is connected to the groundconductor via the introduction portion.

For example, in the main circuit substrate, an integrated circuit for ADconversion for performing digital conversion of the image data isdisposed, in an area near the introduction portion, on the same surfaceas the surface on which the introduction portion is formed.Alternatively, in the main circuit substrate, an integrated circuit forAD conversion for performing digital conversion of the image data isdisposed, in an area opposite to an area of the introduction portion, ona surface reverse of the surface on which the introduction portion isformed.

As described above, in the imaging device of the present disclosure, aload point of the electrically-conductive component is positioned in theload positioning area surrounded by three fixing points on the metalplate, thereby applying a load from the electrically-conductivecomponent to the metal plate in a balanced manner. Therefore, tilting ofthe metal plate is prevented and tilting of the imaging element can beprevented. Therefore, also when the imaging device is used in an intenseelectric field environment, image interference caused by an externalnoise can be reduced while preventing the imaging element from tilting.These and other objects, features, aspects and advantages of the presentdisclosure will become more apparent from the following detaileddescription of the present disclosure when taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view illustrating an outer appearance of adigital camera (which is an exemplary imaging device) according to afirst embodiment;

FIG. 2 is a perspective view of an outer appearance of a camera mainbody from which an exchangeable lens unit is removed;

FIG. 3 is a schematic cross-sectional view of an internal structure ofthe digital camera;

FIG. 4 is a functional block diagram illustrating the digital camera;

FIG. 5 is a cross-sectional view illustrating an internal structure ofthe imaging device, as viewed from thereabove, according to the firstembodiment;

FIG. 6A is a perspective view of a main circuit substrate;

FIG. 6B is a perspective view of the main circuit substrate to which anelectrically-conductive component has been connected;

FIG. 7 illustrates positioning of the electrically-conductive componentrelative to a metal plate;

FIG. 8 illustrates a variation of positioning of a metal-plate-sideconnection component and an elastic component relative to the metalplate;

FIG. 9 illustrates a variation of positioning of the metal-plate-sideconnection component and the elastic component relative to the metalplate;

FIG. 10 illustrates a variation of positioning of the metal-plate-sideconnection component and the elastic component relative to the metalplate;

FIG. 11 is a cross-sectional view illustrating an internal structure ofthe imaging device, as viewed from thereabove, according to the firstembodiment;

FIG. 12 is a cross-sectional view illustrating an internal structure ofan imaging device, as viewed from thereabove, according to a secondembodiment ;

FIG. 13A is a perspective view of a main circuit substrate; and

FIG. 13B is a perspective view of the main circuit substrate to whichthe electrically-conductive component has been connected.

DETAILED DESCRIPTION

Hereinafter, embodiments of the present disclosure will be describedwith reference to the drawings.

First Embodiment

FIG. 1 is a perspective view illustrating an outer appearance of adigital camera (which is an exemplary imaging device) according to afirst embodiment. The digital camera according to the first embodimentincludes a camera main body 1 and an exchangeable lens unit 2 which ismountable to the camera main body 1. FIG. 2 is a perspective view of anouter appearance of the camera main body 1 from which the exchangeablelens unit 2 is removed. FIG. 3 is a schematic cross-sectional view of aninternal structure of the digital camera. FIG. 4 is a functional blockdiagram illustrating the digital camera.

Firstly, referring to FIG. 1 to FIG. 4, a fundamental structure of thedigital camera according to the first embodiment will be described. Inthe description herein, for convenience of description, an object sideof the digital camera is referred to as the front, and an imaging planeside of the digital camera is referred to as the rear or the back.

As shown in FIG. 1, the camera main body 1 includes a main body casing3, a body mount 4, a camera monitor 5, an electronic view finder (EVF)6, and an operation section 7. The body mount 4 is disposed on the frontsurface side of the main body casing 3, and allows the exchangeable lensunit 2 to be mounted to the camera main body 1. The camera monitor 5 isdisposed on the back surface side of the main body casing 3, and isimplemented as a liquid crystal display or the like. The EVF 6 isdisposed on the back surface side of the main body casing 3, anddisplays, for example, an image represented by display image data. Theoperation section 7 is disposed on the top portion of the main bodycasing 3, and includes, for example, a power switch 7 a, and a releasebutton 7 b that receives a shutter operation from a user.

The exchangeable lens unit 2 has, in a lens barrel 2 a made of a resin,an optical system including a group of lenses 28, 29 and 30 that arearrayed on an optical axis AX for forming an optical image of an object.On the outer circumferential portion of the lens barrel 2 a, a zoom ring25, a focus ring 26, and an OIS (Optical Image Stabilizer) switch 27 areprovided. In the exchangeable lens unit 2, positions of lenses in thelens barrel 2 a can be adjusted by rotating the zoom ring 25 and thefocus ring 26.

As shown in FIG. 2, the body mount 4 is structured so as to allow theexchangeable lens unit 2 to be mounted to the camera main body 1. Thebody mount 4 includes a terminal support section 4 a, a body mount ring4 b, and a connection terminal 4 c. On the front surface of the cameramain body 1 on which the exchangeable lens unit 2 is mounted to thecamera main body 1, a shutter unit 12 and a diaphragm 13 are provided.

As shown in FIG. 3, in the main body casing 3 of the camera main body 1,a circuit substrate 9 (mounting component) on which an image sensor 8implemented as a CMOS (Complementary Metal Oxide Semiconductor) or a CCD(Charge Coupled Device) is mounted, and a main circuit substrate 11including a camera controller 10, are provided. Further, in the mainbody casing 3 of the camera main body 1, the body mount 4, the shutterunit 12, the diaphragm 13, an optical low pass filter 14, the imagesensor 8, the circuit substrate 9, a metal component 20, the maincircuit substrate 11, and the camera monitor 5 are disposed in order,respectively, from the front.

A diaphragm support section 13 a supports the diaphragm 13 such that thediaphragm 13 is disposed at a determined position relative to the imagesensor 8. The diaphragm support section 13 a is supported by a mainframe 18 via the body mount 4 and the shutter unit 12. The diaphragm 13and the diaphragm support section 13 a prevent dust from attaching tothe image sensor 8.

The optical low pass filter 14 removes a high frequency component oflight of an object such that an object image which is formed by theexchangeable lens unit 2 has a resolution lower than that based onpitches of pixels of the image sensor 8. In general, in an imagingelement such as the image sensor 8, a color filter, for RGB colors,which includes an array called a Bayer array and/or a complementarycolor filter for YCM colors, are arranged for each pixel. Therefore, ifan image of an object is formed with the same resolution as that of theimage sensor, not only a false color occurs, but also a moiré phenomenonoccurs to make viewing difficult in the case of a repeated pattern of anobject. Therefore, the optical low pass filter 14 is disposed so as toavoid such a problem. The optical low pass filter 14 has an IRprotection filter function for filtering out infrared light.

The main frame 18 that is made of a metal and is disposed in the mainbody casing 3 is connected to the terminal support section 4 a of thebody mount 4, and supports the exchangeable lens unit 2 via the bodymount 4. Further, a tripod mounting section 19 having a screw hole formounting a tripod is mechanically connected to the main frame 18. Thescrew hole of the tripod mounting section 19 is exposed on the bottomsurface of the main body casing 3. Further, the metal component 20disposed so as to surround the circuit substrate 9 to which the imagesensor 8 has been mounted is a component for enhancing dissipation ofheat generated in the image sensor 8. The metal component 20 includes ametal plate 20 a (orthogonal to the optical axis AX) disposed betweenthe circuit substrate 9 and the main circuit substrate 11, and athermally-conductive section 20 b (parallel to the optical axis AX) fortransferring heat from the metal plate 20 a to the body mount 4.

The body mount 4 is a component for mounting the exchangeable lens unit2 to the camera main body 1. The body mount 4 is mechanically andelectrically connected to a lens mount 21 of the exchangeable lens unit2. The body mount 4 includes: a body mount ring 4 b that is made of ametal, is ring-shaped, and is mounted to the front surface of the mainbody casing 3; and the connection terminal 4 c provided in the terminalsupport section 4 a. A connection terminal 21 a provided in the lensmount 21 is electrically connected to the connection terminal 4 c whenthe exchangeable lens unit 2 is mounted to the camera main body 1.

The body mount ring 4 b of the body mount 4 and a lens mount ring 21 bthat is made of a metal and is provided in the lens mount 21 of theexchangeable lens unit 2, fit into each other, whereby the exchangeablelens unit 2 is mechanically held by the camera main body 1. The lensmount ring 21 b fits into the body mount ring 4 b by means of aso-called bayonet mechanism.

Specifically, the lens mount ring 21 b is put into a first state inwhich the lens mount ring 21 b does not fit into the body mount ring 4 bor a second state in which the lens mount ring 21 b fits into the bodymount ring 4 b, according to a relationship in rotated position aboutthe optical axis between the body mount ring 4 b and the lens mount ring21 b. In the first state, the lens mount ring 21 b is movable relativeto the body mount ring 4 b in the optical axis direction, and can beinserted into the body mount ring 4 b. When the lens mount ring 21 b isrotated relative to the body mount ring 4 b in a state where the lensmount ring 21 b has been inserted into the body mount ring 4 b, the lensmount ring 21 b fits into the body mount ring 4 b. At this time, arelationship in rotated position between the body mount ring 4 b and thelens mount ring 21 b represents the second state.

Further, the connection terminal 4 c electrically contacts with theconnection terminal 21 a of the lens mount 21 in a state where theexchangeable lens unit 2 is mounted to the camera main body 1. Thus, thebody mount 4 and the lens mount 21 are electrically connected to eachother via the connection terminal 4 c of the body mount 4 and theconnection terminal 21 a of the lens mount 21. As a result, in thedigital camera, image data signals and control signals can betransmitted and received between the camera main body 1 and theexchangeable lens unit 2 via the body mount 4 and the lens mount 21.

Referring to FIG. 4, an internal function of the camera main body 1 willbe firstly described in detail.

The body mount 4 and the lens mount 21 are connected to each other suchthat image data and control signals can be transmitted and receivedbetween the camera controller 10 and a lens controller 22 provided inthe exchangeable lens unit 2. Further, in the main body casing 3, apower supply block 15 implemented as, for example, a battery is providedfor supplying power to each component such as the camera controller 10.The power supply block 15 also supplies power to the entirety of theexchangeable lens unit 2 via the body mount 4 and the lens mount 21.

The image sensor 8 operates based on a timing signal supplied from atiming signal generator (TG) 9 a mounted to the circuit substrate 9, andconverts, to image data, an object image which is an optical image of anobject obtained via the exchangeable lens unit 2, to generate stillimage data, moving image data, or the like. Image data, such as thestill image data or moving image data, generated by the image sensor 8is converted to a digital signal by an ADC (analog-to-digital converter)9 b mounted to the circuit substrate 9, and is subjected to variousimage processing by the camera controller 10. The various imageprocessing performed by the camera controller 10 includes, for example,a gamma correction process, a white balance correction process, a flawcorrection process, a YC conversion process, an electronic zoom process,and a JPEG compression process. The function of the circuit substrate 9may be included in the main circuit substrate 11.

Further, the image data generated by the image sensor 8 is used fordisplaying a through-the-lens image. The through-the-lens image is animage represented by moving image data, and the data of thethrough-the-lens-image is not stored in a memory card 16. Thethrough-the-lens image is displayed on the camera monitor 5 and/or theEVF 6 in order to compose a moving image or a still image.

The camera controller 10 is mounted to the main circuit substrate 11.The camera controller 10 controls each component of the camera main body1, and transmits a signal for controlling the exchangeable lens unit 2,to the lens controller 22, via the body mount 4 and the lens mount 21.On the other hand, the camera controller 10 receives various signalsfrom the lens controller 22 via the body mount 4 and the lens mount 21.Thus, the camera controller 10 indirectly controls each component of theexchangeable lens unit 2.

Further, the camera controller 10 uses, as a work memory, a DRAM 11 amounted to the main circuit substrate 11 during a control operation andan image processing operation. Further, a card slot 17 is formed forinputting from and outputting to the memory card 16 mounted to thecamera main body 1 still image data and moving image data, according toa control signal transmitted from the camera controller 10.

The shutter unit 12 is a so-called focal plane shutter. The shutter unit12 is disposed between the body mount 4 and the image sensor 8, and canshield the image sensor 8 from light. The shutter unit 12 includes afirst shutter curtain, a second shutter curtain, and a shutter supportframe having an opening through which light is guided from an object tothe image sensor 8. The shutter unit 12 moves to or retracts from theopening of the shutter support frame the first shutter curtain and thesecond shutter curtain, to adjust an exposure time of the image sensor8.

Next, an internal function of the exchangeable lens unit 2 will bedescribed in detail.

The exchangeable lens unit 2 has, in the lens barrel 2 a made of aresin, the optical system including a group of lenses 28, 29 and 30arrayed on the optical axis AX for forming an optical image of anobject, the lens mount 21, the lens controller 22, an aperture unit 23,and a driving section 24 for driving the group of lenses 28, 29 and 30of the optical system.

Further, the zoom ring 25, the focus ring 26, and the OIS switch 27 areprovided on the outer circumferential portion of the lens barrel 2 a.The exchangeable lens unit 2 is allowed to adjust positions of thelenses in the lens barrel 2 a by the zoom ring 25 and the focus ring 26being rotated.

The optical system has a group of lenses 28 for zooming, a group oflenses 29 for OIS, and a group of lenses 30 for focusing. The group oflenses 28 for zooming operates so as to change a focal distance of theoptical system. The group of lenses 29 for OIS operates so as torestrain, for the image sensor 8, blurring of an object image which isformed by the optical system. The group of lenses 30 for focusingoperates so as to change a focus state of an object image formed on theimage sensor 8 by the optical system.

The aperture unit 23 is a light amount adjustment component that adjustsan amount of light transmitted through the optical system. Specifically,the aperture unit 23 includes aperture blades that can block a portionof light beams transmitted through the optical system, and an aperturedriving section for driving the aperture blades.

The driving section 24 drives the group of lenses 28, 29 and 30 of theoptical system described above, based on a control signal from the lenscontroller 22. The driving section 24 has a detection section fordetecting positions of the group of lenses 28, 29 and 30 of the opticalsystem.

The lens controller 22 controls the entirety of the exchangeable lensunit 2 based on a control signal transmitted from the camera controller10 of the camera main body 1. The lens controller 22 receives positionalinformation of the group of lenses 28, 29 and 30 of the optical systemas detected by the detection section of the driving section 24, andtransmits the positional information to the camera controller 10. Thecamera controller 10 generates a control signal for controlling thedriving section 24 based on the positional information received from thelens controller 22, and transmits the control signal to the lenscontroller 22.

The lens controller 22 transmits, to the driving section 24, the controlsignal generated by the camera controller 10. The driving section 24adjusts positions of the group of lenses 28, 29 and 30 based on thecontrol signal transmitted from the lens controller 22.

On the other hand, the camera controller 10 generates a control signalfor operating the aperture unit 23, based on information indicating, forexample, an amount of light received by the image sensor 8, whether astill image is to be photographed or a moving image is to bephotographed, and whether or not an operation is being performed so asto preferentially set an aperture value. At this time, the lenscontroller 22 relays the control signal generated by the cameracontroller 10, to the aperture unit 23.

A DRAM 22 a and a flash memory 22 b are held in the exchangeable lensunit 2. The lens controller 22 uses the DRAM 22 a as a work memory whendrives the group of lenses 28, 29 and 30 of the optical system and theaperture unit 23. In the flash memory 22 b, programs and parameters usedby the lens controller 22 are stored.

Thus, the digital camera (which is an exemplary imaging device)according to the first embodiment has been described with reference toFIG. 1 to FIG. 4. However, the imaging device may be another imagingdevice which uses an electrically-conductive component connectingbetween a metal plate described below, and the main circuit substrate.

Hereinafter, connection between a metal plate and GND of the maincircuit substrate will be described in detail as means for reducingimage interference caused by an external nose. The “GND” may berepresented as “ground” or “earth.”

FIG. 5 is a cross-sectional view illustrating an internal structure ofan imaging device 100, as viewed from thereabove, according to the firstembodiment. In the description herein, control of a GND potential by ametal plate 150 will be mainly described, and detailed description ofmatters other than the control is omitted. The fundamental structure ofthe imaging device 100 is the same as described for the digital camerawith reference to FIG. 1 to FIG. 4.

As shown in FIG. 5, the imaging device 100 includes an imaging element110, a main circuit substrate 120, an imaging element flexible cable130, a mount 140, an exchangeable lens mount section 145, a metal plate150, connection sections 160, elastic components 165, and anelectrically-conductive component 190. The electrically-conductivecomponent 190 is formed of a metal having a high electricalconductivity. The main circuit substrate 120 has a GND removal portion180, as described below, on the front surface on the metal plate 150side. Further, the main circuit substrate 120 has an AD conversion LSI185 for performing a digital conversion of image data generated by theimaging element 110, on the back surface on a side opposite to the metalplate 150 side. The AD conversion LSI 185 is disposed on the backsurface of the main circuit substrate 120 in an area opposite to an areaof the GND removal portion 180 to which the electrically-conductivecomponent 190 is connected.

The imaging element 110 is implemented as, for example, a CMOS or a CCD,and corresponds to the image sensor 8 described above. On the frontsurface of the imaging element 110, an object image which is an opticalimage of an object obtained via the group of lenses 28, 29 and 30, isformed. The imaging device 110 converts the object image into imagedata, to generate still image data, moving image data, or the like.

The main circuit substrate 120 corresponds to the main circuit substrate110 described above. The main circuit substrate 120 includes the cameracontroller 10 that performs various signal processing of the image datagenerated by the imaging element 110. In the description herein, thevarious signal processing is the image processing described above, andincludes, for example, a gamma correction process, a white balancecorrection process, a flaw correction process, a YC conversion process,an electronic zoom process, and a JPEG compression process. The maincircuit substrate 120 is a rectangular substrate having an area greaterthan that of the imaging element 110. The main circuit substrate 120 isfixed to the main body casing 3 behind the imaging element 110 so as tobe almost parallel to the imaging element 110. Further, the main circuitsubstrate 120 is a multilayered substrate having a GND layer (GNDconductor) thereinside. On the main circuit substrate 120, the GNDremoval portion 180 is formed as an exposed portion of the GND layer bya portion of an insulating layer that covers the GND layer beingremoved.

The imaging element flexible cable 130 has four cable end connectionportions that are connected to the main circuit substrate 120, and isformed so as to be roughly H-shaped. The imaging element flexible cable130 includes a pair of band portions each having the cable endconnection portions on both ends, and a rectangular central connectionportion connecting between central portions of the paired band portions.The paired band portions are spaced from each other and extend parallelto each other. In the imaging element flexible cable 130, the bandportions correspond to longitudinal lines, respectively, of the H shape,and the central connection portion corresponds to a transverse line ofthe H shape. The imaging element flexible cable 130 corresponds to, forexample, the circuit substrate 9 (mounting component) described above,and allows the imaging element 110 to be mounted to the centralconnection portion. The imaging element 110 is mounted so as to protrudefrom the central connection portion toward each band portion. Aplurality of signal lines are embedded in each band portion so as toextend from each cable end connection portion to the imaging element110. The imaging element flexible cable 130 is supported by the maincircuit substrate 120 by each cable end connection portion beingconnected to the main circuit substrate 120.

The mount 140 corresponds to, for example, the body mount 4 describedabove. The mount 140 is a component for allowing the lens unit 2 to bemounted to the main body casing 3. The mount 140 is fixed to the mainbody casing 3 and has a GND potential. The mount 140 is disposed infront of the imaging element 110. The mount 140 also secures an SSWF(Super Sonic Wave Filter) (not shown) for removing dust on the surfaceof the imaging element 110, a shutter unit (not shown), and a flash unit(not shown). Further, the mount 140 is formed of a metal material suchas aluminum or a stainless steel (SUS), in order to enhance reliabilityin heat-dissipation and reliability against drop impact, and to addressunnecessary electromagnetic radiation. The exchangeable lens mountsection 145 corresponds to the lens mount 21 described above.

The metal plate 150 is formed in a roughly rectangular shape. The metalplate 150 is disposed between the imaging element 110 and the maincircuit substrate 120. The metal plate 150 is provided so as to bealmost parallel to the main circuit substrate 120. The metal plate 150is electrically connected to the GND removal portion 180 of the maincircuit substrate 120 via the electrically-conductive component 190. Aconnection portion between the GND removal portion 180 and theelectrically-conductive component 190 will be described below in detail.

Further, the metal plate 150 corresponds to, for example, the metalplate 20 a of the metal component 20 described above. The metal plate150 is fixed to a mounting area of the imaging element flexible cable130 in which the imaging element 110 is mounted, or disposed near themounting area, in order to transfer heat generated in the imagingelement 110. In the first embodiment, the metal plate 150 is adhered toan area opposite to the mounting area. The metal plate 150 is formed ofa metal material, such as aluminum or copper, having a high thermalconductivity and electrical conductivity, to efficiently dissipate heattransferred from the imaging element 110. A portion at which the metalplate 150 is mounted to the mounting area is not limited to an areaopposite to the mounting area.

The connection sections 160 are components that extend forward from themetal plate 150 so as to fix the metal plate 150 to the mount 140 atthree or more fixing points. In the first embodiment, the number of thefixing points is three. The connection sections 160 have an electricalconductivity. The connection sections 160 electrically connect betweenthe mount 140 and the metal plate 150 via the elastic components 165provided at each fixing point. The connection sections 160 are fixed tothe mount 140 at each fixing point by the use of screws formed of ametal material in a state where the connection sections 160 are urged bythe elastic components 165. When the camera main body 1 is assembled,before an assembly in which the mount 140 and the metal plate 150 areconnected to each other via the connection sections 160, is fixed to themain body casing 3, the screw at each fixing point is screwed to adjustthe tilting of the metal plate 150. In the assembly, the imaging elementflexible cable 130 and the imaging element 110 are also mounted to themetal plate 150. The connection sections 160 connect between the mount140 and the metal plate 150 via the elastic components 165. The elasticcomponents 165 are elastically deformable so as to allow the tilting ofthe metal plate 150 to be adjusted. The shape of each elastic component165 is not limited to the shape shown in FIG. 5. Further, the connectionsections 160 may be formed of, for example, a steel material which isless likely to be elastically deformed, as a part of the metal plate150. In this case, for example, the outer circumferential portion of themetal plate 150 is bent toward the front surface side, to form theconnection sections 160 that protrude from a main body portion of themetal plate 150 toward the mount 140. Further, in the descriptionherein, the “fixing point” does not represent a point having no area,unlike that represented by a mathematical term. A “fixing point” may berepresented as a “fixing portion.”

Next, a connection portion between the main circuit substrate 120 andthe electrically-conductive component 190 will be specificallydescribed. FIG. 6A is a perspective view of the main circuit substrate120. As shown in FIG. 6A, the main circuit substrate 120 has the GNDremoval portion 180 on the front surface on the metal plate 150 side.The GND removal portion 180 is an area on the front surface of the maincircuit substrate 120 in which a resist is removed, and has a GNDpotential. FIG. 6B is a perspective view of the main circuit substrate120 to which the electrically-conductive component 190 has beenconnected. As shown in FIG. 6B, on the main circuit substrate 120, theGND removal portion 180 and the electrically-conductive component 190are connected to each other. The shape of the electrically-conductivecomponent 190 is not limited to the shape shown in FIG. 5 and FIG. 6B.Further, an area of a portion in which the electrically-conductivecomponent 190 contacts with the metal plate 150 is favorably great inlight of heat dissipating performance and the like.

FIG. 7 illustrates positioning of the electrically-conductive component190 relative to the metal plate 150. FIG. 7 illustrates the metal plate150 as viewed from the back surface side of the imaging device 100. FIG.7 illustrates the back surface of the metal plate 150 as viewed in thedirection orthogonal thereto. As shown in FIG. 7, the connectionsections 160 of the metal plate 150 are fixed to the mount 140 at threefixing points. The right angle degree of the imaging element 110(namely, the degree to which an angle between the optical axis AX andthe imaging element 110 is proximate to the right angle) is defined byelastic force of the elastic components 165.

A triangular area surrounded by the three elastic components 165 (thethree fixing points) is referred to as a load positioning area 195 inthe case of the back surface of the metal plate 150 being viewed in thedirection orthogonal thereto. The electrically-conductive component 190is disposed so as to position a load point 196 of theelectrically-conductive component 190 in the load positioning area 195.The load point 196 of the electrically-conductive component 190 is acontact point between the electrically-conductive component 190 and themetal plate 150, and represents an area in which a load (pressing load)is applied from the electrically-conductive component 190 to the metalplate 150. When the electrically-conductive component 190 is thusdisposed, a load is applied from the electrically-conductive component190 to the metal plate 150 in a balanced manner. Therefore, tilting ofthe metal plate 150 can be prevented, and tilting of the imaging element110 can be prevented. The connection sections 160 may be fixed at fouror more fixing points via the elastic components 165. Further, eachconnection section 160 may diverge into a plurality of portions in themid-portion thereof, and the diverging heads may be fixed to the mount140 via the elastic components 165. The electrically-conductivecomponent 190 may be merely connected to the metal plate 150 withoutapplying a pressing load from the electrically-conductive component 190to the metal plate 150 in a state where the imaging element 110 ispositioned so as to be orthogonal to the horizontal direction.

Further, the electrically-conductive component 190 may be disposed suchthat the load point 196 of the electrically-conductive component 190 ispositioned on the metal plate 150 in or near an area (hereinafter,referred to as an opposite area 197 that is an area opposite to an areaof the imaging element 110) just opposite to an area in which theimaging element 110 is disposed in the case of the back surface of themetal plate 150 being viewed in the direction orthogonal thereto. Inother words, the opposite area 197 is an area in which the metal plate150 and the imaging element 110 overlap each other in the case of theback surface of the metal plate 150 being viewed in the direction(direction orthogonal to the metal plate 150) orthogonal thereto (asviewed through the metal plate 150). When the electrically-conductivecomponent 190 is thus disposed, an impedance of GND of the opposite area197 near the imaging element 110 in the metal plate 150 is reduced,whereby an influence of an external electromagnetic wave which entersthe imaging element 110 can be effectively eliminated.

Although, in the example shown in FIG. 7, the number of the load points196 of the electrically-conductive component 190 is one, the number ofthe load points 196 of the electrically-conductive component 190 may begreater than or equal to two. However, in a case where the number of theload points 196 of the electrically-conductive component 190 is greaterthan or equal to two, at least one load point is positioned in the loadpositioning area 195 or in the opposite area 197 that is an areaopposite to an area of the imaging element 110 as described above.Further, the opposite area 197 that is an area opposite to an area ofthe imaging element 110 may overlap the load positioning area 195. Inthis case, the electrically-conductive component 190 may be disposed soas to position the load point 196 in an area, on the metal plate 150, inwhich the load positioning area 195 overlaps the opposite area 197 thatis an area opposite to an area of the imaging element 110. In suchpositioning, tilting of the imaging element 110 can be prevented, and aninfluence of an external electromagnetic wave which enters the imagingelement 110 can be efficiently eliminated.

Further, the electrically-conductive component 190 may be anelectrically-conductive elastic component 190 having an elastic functionin addition to electrical conductivity. The electrically-conductiveelastic component 190 is formed of a metal, such as aluminum and copper,having a high electrical conductivity, in an elastically deformableshape. When the electrically-conductive component 190 has an elasticfunction, a stress applied to the metal plate 150 adhered to themounting area is reduced. As a result, generation of stress applied tothe imaging element 110 is restrained, and tilting of the imagingelement 110 can be restrained.

It is assumed that, for example, a compression load F1 is applied fromthe mount 140 toward each connection section 160 at a corresponding oneof the elastic components 165 provided between the mount 140 and theconnection section 160 in a state where the optical axis AX is in ahorizontal state (a state where the imaging element is positioned so asto be orthogonal to the horizontal direction). Further, it is assumedthat a compression load F2 is applied from the main circuit substrate120 toward the metal plate 150 at the electrically-conductive elasticcomponent 190 provided between the main circuit substrate 120 and themetal plate 150. In this case, a sum of the compression loads applied toall the elastic components 165 is made greater than the compression loadapplied to the electrically-conductive elastic component 190. Forexample, when the compression loads F1 applied to all the elasticcomponents 165, respectively, are equal to each other, a relationship ofmF1>F2 is satisfied. m represents the number of the elastic components165, and represents an integer greater than or equal to three. When thisrelationship is satisfied, a load applied from theelectrically-conductive elastic component 190 to the metal plate 150 canbe reduced. Therefore, titling of the metal plate 150 can be prevented,and titling of the imaging element 110 can be prevented.

The number of the electrically-conductive components 190 (theelectrically-conductive elastic components 190) provided in the imagingdevice 100 may be plural and the number of the GND removal portions 180provided in the imaging device 100 may be plural. In such a case, it isassumed that a load F2 is applied from the main circuit substrate 120toward the metal plate 150 at each electrically-conductive elasticcomponent 190 provided between the main circuit substrate 120 and themetal plate 150 in a state where the optical axis AX is in a horizontalstate. In this case, a sum of compression loads applied to all theelastic components 165 is made greater than compression loads applied toall the electrically-conductive elastic components 190. For example,when the compression loads F1 applied to all the elastic components 165,respectively, are equal to each other, and the compression loads F2applied to all the electrically-conductive elastic components 190,respectively, are equal to each other, a relationship of mF1>nF2 issatisfied. m represents the number of the elastic components 165, andrepresents an integer greater than or equal to three. n represents thenumber of the electrically-conductive elastic components 190, andrepresents an integer greater than or equal to two. Namely, also whenthe number of the load points 196 of the electrically-conductive elasticcomponent 190 is plural, a similar relationship is satisfied.

Next, variations of positioning of the connection sections 160 and theelastic components 165 relative to the metal plate 150 will bedescribed. FIGS. 8 to 10 illustrate variations of positioning of theconnection sections 160 and the elastic components 165 relative to themetal plate 150. As shown in FIGS. 8 to 10, the metal plate 150 may befixed to the mount 140 in a balanced manner by means of at least threesets of the connection sections 160 and the elastic components 165.

Further, the imaging device 100 may be structured as shown in, forexample, FIG. 11. In the imaging device 100 shown in FIG. 11, an imagingelement substrate 115 (mounting component) is mounted on the imagingelement flexible cable 130, and the imaging element 110 is mounted onthe imaging element substrate 115.

As described above, in the imaging device 100 according to the firstembodiment, the GND removal portion 180 of the main circuit substrate120 and the metal plate 150 are electrically connected to each other viathe electrically-conductive component 190, to reduce an impedance of GNDof the metal plate 150. As a result, variation in GND potential in theimaging element 110 can be restrained.

Further, the electrically-conductive component 190 is disposed so as toposition the load point 196 of the electrically-conductive component 190in the load positioning area 195, on the metal plate 150, surrounded bythe three elastic components 165, thereby applying a load from theelectrically-conductive component 190 to the metal plate 150 in abalanced manner. Therefore, titling of the metal plate 150 can beprevented, and tilting of the imaging element 110 can be prevented.

Further, in the imaging device 100 according to the first embodiment, anelectrically conductive filter for reducing an amount of light incidenton the lenses is not used. Therefore, also when the imaging device isused in an intense electric field environment, an image interferencecaused by an external noise can be reduced without deteriorating animage quality of a captured image. Further, the electrically-conductivecomponent 190 is not so great component, and has a simplified internalconfiguration, thereby downsizing the imaging element.

Second Embodiment

FIG. 12 is a cross-sectional view illustrating an internal structure ofan imaging device 200, as viewed from thereabove, according to a secondembodiment. In description herein, difference from the first embodimentwill be mainly described. A fundamental configuration of the imagingdevice 200 is the same as that of the digital camera described withreference to FIG. 1 to FIG. 4.

As shown in FIG. 12, the imaging device 200 includes the imaging element110, the main circuit substrate 120, the imaging element flexible cable130, the mount 140, the exchangeable lens mount section 145, the metalplate 150, the connection sections 160, the elastic components 165, andthe electrically-conductive component 190. Further, the main circuitsubstrate 120 has the GND removal portion 180 and the AD conversion LSI185 (an integrated circuit for AD conversion) on the front surface onthe metal plate 150 side. In FIG. 12, the same components as describedfor the imaging device 100, as shown in FIG. 5, according to the firstembodiment are denoted by the same reference numerals, and detaileddescription thereof is omitted. In the description herein, differencefrom the first embodiment will be mainly described.

The imaging device 200 according to the second embodiment is differentfrom the imaging device 100 according to the first embodiment in that,in the second embodiment, the AD conversion LSI 185 is mounted on thefront surface (namely, the same surface as the surface on which the GNDremoval portion 180 is formed) of the main circuit substrate 120 on themetal plate 150 side. The AD conversion LSI 185 is disposed, on thefront surface of the main circuit substrate 120, in an area near the GNDremoval portion 180 to which the electrically-conductive component 190is connected. FIG. 13A is a perspective view of the main circuitsubstrate 120. In FIG. 13A, the main circuit substrate 120 has the GNDremoval portion 180 and the AD conversion LSI 185 on the same surface.FIG. 13B is a perspective view of the main circuit substrate 120 towhich the electrically-conductive component 190 has been connected. Asshown in FIG. 13B, the GND removal portion 180 and theelectrically-conductive component 190 are connected to each other on themain circuit substrate 120.

As described above, with the imaging device 200 according to the secondembodiment, the same effect as in the first embodiment can be obtained.Namely, in the imaging device 200 according to the second embodiment,also when the imaging device is used in an intense electric fieldenvironment, an image interference caused by an external noise can bereduced without deteriorating an image quality of a captured image.Further, the internal configuration is simplified, thereby downsizingthe imaging element.

While the disclosure has been described in detail as above, theforegoing description is in all aspects illustrative and notrestrictive. It will be understood that numerous other modifications andvariations can be devised without departing from the scope of thedisclosure.

What is claimed is:
 1. An imaging device for taking an image of an object, the imaging device comprising: an imaging element configured to capture an optical image of an object, and generate image data; a main circuit substrate, disposed behind the imaging element, configured to perform signal processing of the image data generated by the imaging element; a mounting component configured to mount the imaging element; a metal plate, disposed between the mounting component and the main circuit substrate, having a front surface on which the mounting component is mounted; a mount, disposed in front of the metal plate, configured to support the metal plate by connection sections extending forward from the metal plate being fixed at at least three fixing points; a plurality of elastic components, provided at each fixing point of the mount, configured to urge the connection sections; and an electrically-conductive component configured to electrically connect between a ground conductor of the main circuit substrate and the metal plate, wherein the electrically-conductive component is disposed such that a connection point with the metal plate is positioned in a area which is formed by the at least three fixing points being sequentially connected in the case of a back surface of the metal plate being viewed in a direction orthogonal thereto.
 2. The imaging device according to claim 1, wherein the connection point is positioned in an area in which the metal plate and the imaging element overlap each other in the case of the back surface of the metal plate being viewed in the direction orthogonal thereto.
 3. The imaging device according to claim 1, wherein the electrically-conductive component is an electrically-conductive elastic component formed to be elastically deformable.
 4. The imaging device according to claim 3, wherein a compression load from the mount toward the metal plate is applied to each elastic component, and in a case where a compression load from the main circuit substrate toward the metal plate is applied to the electrically-conductive elastic component, in a state where the imaging element is positioned to be orthogonal to a horizontal direction, a sum of compression loads applied to all the elastic components is greater than the compression load applied to the electrically-conductive elastic component when the number of the electrically-conductive elastic components is one, and a sum of compression loads applied to all the elastic components is greater than a sum of compression loads applied to all the electrically-conductive elastic components when the number of the electrically-conductive elastic components is plural.
 5. The imaging device according to claim 1, wherein the main circuit substrate has the ground conductor embedded therein, and in the main circuit substrate, an introduction portion is formed, as an opening or a cut portion, in a portion of an insulating layer that covers the ground conductor, on a surface on the metal plate side, and the electrically-conductive component is connected to the ground conductor via the introduction portion.
 6. The imaging device according to claim 5, wherein, in the main circuit substrate, an integrated circuit for AD conversion for performing digital conversion of the image data is disposed, in an area near the introduction portion, on the same surface as the surface on which the introduction portion is formed.
 7. The imaging device according to claim 5, wherein, in the main circuit substrate, an integrated circuit for AD conversion for performing digital conversion of the image data is disposed, in an area opposite to an area of the introduction portion, on a surface reverse of the surface on which the introduction portion is formed. 